Nanocellulose- and lignin-based corrosion inhibitor technologies for organic coatings: A systematic review

The transition toward sustainable corrosion protection has accelerated interest in bio-derived coating systems, particularly nanocellulose, cellulose derivatives, and lignin-based materials. However, the field remains fragmented due to variations in material structure, modification strategies, coating matrices, and evaluation methods, limiting meaningful comparison across studies. This systematic review critically evaluates recent advances in nanocellulose- and lignin-based coatings for corrosion protection using a PRISMA-guided literature selection.The analysis reveals that corrosion resistance arises from the synergistic interplay of interfacial adsorption, barrier reinforcement, and electrochemical stabilization. Cellulose derivatives primarily act through adsorption-driven inhibition, while nanocellulose-reinforced polymer coatings enhance protection via reduced porosity and tortuous diffusion pathways. Lignin-based systems contribute additional functionality through aromatic interactions, passive-film stabilization, and redox activity, particularly in hybrid coatings.Although inhibition efficiencies exceeding 90% are frequently reported, direct comparison across studies is complicated by differences in testing methodologies and coating architectures. Key factors governing performance include nanofiller morphology, surface functionality, matrix compatibility, and dispersion quality. Despite promising laboratory results, challenges remain in long-term durability, standardization of testing protocols, and regulatory considerations for nano-enabled systems.By integrating mechanistic understanding with comparative performance analysis, this review provides a structured framework for interpreting current research and identifies critical directions for the rational design and industrial translation of sustainable anticorrosion coatings.